Apparatus and method for minimizing waste and improving quality and production in web processing operations by automatic narrow web twist defect correction

Abstract

Apparatus and methods are provided to minimize waste and improve quality and production in web processing operations. The apparatus and methods provide defect detection in deposition of acquisition material, which on current machines frequently flips and is difficult to detect when it has flipped causing manufacturers to scrap thousands of products. Using the present invention, defects are able to be detected by discerning a difference in the appearance from side to side with a vision camera, and an acquisition inverter can flip the material to a correct orientation.

Description

RELATED APPLICATION[0001]This application claims the benefit of co-pending U.S. Provisional Patent Application Serial No. 61 / 450,990, filed 9 Mar. 2011.BACKGROUND OF THE INVENTION[0002]The invention disclosed herein relates to apparatus and methods for waste reduction and improvements to the quality and production in web processing operations, such as diaper manufacturing. While the description provided relates to diaper manufacturing, the apparatus and method are easily adaptable to other applications.[0003]Generally, diapers comprise an absorbent insert or patch and a chassis, which, when the diaper is worn, supports the insert proximate a wearer's body. Additionally, diapers may include other various patches, such as tape tab patches, reusable fasteners and the like. The raw materials used in forming a representative insert are typically cellulose pulp, tissue paper, poly, nonwoven web, acquisition, and elastic, although application specific materials are sometimes utilized. Usua...

AI Technical Summary

Benefits of technology

[0020]Provided are method and apparatus for minimizing waste and improving quality and production in web processing operations.

[0021]Importantly, the methods taught in the present application are applicable not only to diapers and the like, but in any web based operation. The waste minimization techniques taught herein can be directed any discrete component of a manufactured article, i.e., the methods taught herein are not product specific. For instance, the present methods can be applied as easily with respect to diaper components as they can for feminine hygiene products, as they can for face masks in which components such as rubber bands and nose pieces are used.

[0022]For instance, by practicing the methods of the present invention, waste of staples and elastic bands can be avoided during manufacture of face masks, for instance those disclosed in U.S. Pat. No. 7,131,442. One of the objectives is simply to recognize product during manufacture that ultimately would fail quality control inspection, and avoid placing material on to that product during the manufacturing processes.

[0023]As another example, the amount of adhesive applied to certain products can be reduced by not applying adhesive to products that have already been determined to be defected or assigned to rejection. For instance, in U.S. Pat. No. 6,521,320, adhesive application is shown for example in FIG. 11. By assigning or flagging product that has already been determined to end up in a scrap or recycling pile, the adhesive flow can be stopped or minimized.

[0024]In yet another exemplary application of the methods of the present invention, discrete components or raw material carried on products that have already been determined to be defected or assigned to rejection can also be removed and recycled prior to commingling with other discrete components or raw material. For instance, if an absorbent pad, such as shown at reference numeral 40 of U.S. Pat. No. 6,521,320 is destined for application to a product that has already been determined to be defected or assigned to rejection, the absorbent pad can be withdrawn from the product, or never introduced in the first instance. For example, during startup or shutdown of high speed diaper manufacturing operations, a certain number of products is routinely discarded into recycling. By identification of the start up or shut down routine, avoidance of introduction of absorbent pads can be achieved. Alternatively, during stand-by, the absorbent pads often degrade by accumulation of dust. By identifying which products would bear the dust, the absorbent pads can be withdrawn from further manufacture, and no additional components would be applied to such a product.

Problems solved by technology

SAP is generally excellent at liquid storage, but because SAP turns to a gelatinous type material, does not distribute liquid well.

As in many manufacturing operations, waste minimization is a goal in web processing applications, as products having spliced raw materials cannot be sold to consumers.

Indeed, due to the rate at which web processing machines run, even minimal waste can cause inefficiencies of scale.

However, the act of harvesting recyclable materials from defective product is intensive.

If the narrow webs become twisted, the twist often persists in the form of an undesirable overlap of material.

This often has required operators to undesirably stop the machine and manually remove the twist from the web.

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